David Cameron has promised an In-Out referendum on the EU in the next Parliament. Why, then, do some of his backbenchers want a mandate referendum now, and still more of them want to write the In-Out referendum into law? There is no simple answer, but a number of different factors have come together. One is the passion that the EU has excited within the Conservative Party since Bruges. Another is fear of UKIP. Still another is the belief, common among Tory MPs, that Cameron is very unlikely to lead a majority Conservative Government after 2015. But, above all perhaps, there is, at worst, a distrust of the Prime Minister over Europe and, at best, the conviction among Tory MPs that on the issue he will follow rather than lead.

Cameron's gambit yesterday evening was crafted to ward off accusations of followership after a day in which party debate over the Baron/Bone amendment to the Queen's Speech, and over the EU itself, threatened to run out of control. The device of a Private Member's Bill is the best he can do to regain the initiative – since Nick Clegg will not concede a Government Bill, even on a free vote, and there is nothing the Prime Minister can do to master him, short of breaking up the Coalition altogether. Such a Bill is unlikely to deliver the goods, since such measures are vulnerable to being talked out. Ed Miliband's main aim will be to obscure his party's own differences on the EU, and to out-manoevre Cameron when MPs vote in the Commons – in alliance, probably, with the Liberal Democrats.

Many of the MPs who have backed the Baron/Bone amendment won't give up if a Private Members' Bill goes down. They will seek every conceivable means of raising the referendum issue in the Commons. It is tempting to write them all off, as the Prime Minister doubtless already does, as a crocodile which, if fed with concessions, will always demand more – and ultimately eat up Cameron himself, and his party's electoral chances with it. It is true that many over-estimate the salience of the EU issue to voters; that some are beyond caring about the compromises inherent in coalition, and that others would be happy to see the Coalition break up, even if a general election followed. But most Tory MPs are not irrational. They simply want their leader to lead – as he is now trying to do. None the less, the hard truth is that it may be too late.

Cameron is in many respects unlike John Major, the last Conservative Prime Minister to precede him. He is brighter, more agile, less prone to complaint and self-pity, more of a natural leader. But he is now in much the same fragile place with his party on Europe as Major was, and for the same reason: he has failed to lead. At first glance, this is a harsh conclusion. But isn't his concession of a private member's bill, wrung out of him after almost a week of prevarication, evidence that the claim is right? After his election as Tory leader, he took one bold decision – in effect, to take Conservative MEPs out of the European People's Party. Since then, his inclination on Europe policy has been to avoid it whenever possible. His treaty veto, brave and welcome though it was, was essentially reactive – tactical, rather than strategic.

Hence the blow to his reputation over the Lisbon referendum, the late concession of an In-Out referendum and the obscurity over which powers he wants to see repatriated. And now he has lost control of his Cabinet on the issue – just as a public spending round looms. Tim Montgomerie has named nine Cabinet Ministers as "Outers" – at least, were a referendum to be held today. Two of them are Philip Hammond, who has followed Michael Gove, who has now set out publicly what he had said privately last October. Indeed, Boris Johnson's riddling article on Europe yesterday can be seen as a response to Gove's clarity. There is even a case for saying that the Education Secretary, with his brains, energy and fearlessness, is emerging as the real Conservative leader.